Unfortunately I don't have the bill at hand so I can't list any specific details; all I know is that we're registered with NPower. We got an electricity bill from them yesterday, and for a quarter they charged us around £155. I mentioned it to my mum this afternoon, not really thinking much of it, but she was a bit puzzled and said that her quarterly bill had just come through and hers was only £60. She's with EDF.

I don't know what product tarriff we're signed up to; I do know, however, that we pay quarterly by Direct Debit and we're charged according to the prices set for the Salford area (though when I checked the unit prices online they made virtually no sense to me). The house is semi-detached with gas central heating. All the lightbulbs are energy savers, and we switch virtually everything off at the walls if we're not using them, except for the fridge and hot water tank in the airing cupboard. Sometimes my boyfriend leaves his laptop plugged in and switched on overnight if he's downloading something, and during the day most of us have our laptops switched on at the wall, although when we have enough power to run off the battery then we unplug them. At my mum's house, on the other hand, tons of stuff is left switched on at the wall, including most non-essential items, such as the TV and DVD player, all the computer equipment in my step dad's work room, all the plug extenders, and so on. Our suppliers aren't the same, but is £155 steep for a quarterly bill? Apparently we've been undercharged on this one, too. They've not charged us for 400 units, though I don't know what that's worth.

Sorry if this all seems a bit jumbled! Can anyone give me a round-about figure for what I could or should be paying per quarter with NPower?

It sounds very steep for quarterly to me... how much electricity are you using? My mum got stung by them because she was paying £x each month, and so in the summer she was paying a bit over, and in the winter she was paying a bit under, and it worked out that she was even overall. But they didnt tell her that she actually wasnt paying enough and she got stung with like a £500 bill...

I'd look at your itemised bill, see if there's anything you can do to cut back on power. In my house we unplug everything, every night before we go to bed.

@ Ruth: At the moment I don't know how much we're using, I'll find out as soon as I go back on Sunday. As for cutting back, I honestly don't think there's much else we can possibly cut back on. We're very careful as it is. Like I said, all the lightbulbs are energy savers and nothing is left switched on at the wall during the day or night, except the fridge and the water tank in the airing cupboard.

@ Dispy: The house isn't particularly large. The kitchen and dining room are both very modest, there's only one double bedroom, and the other two bedrooms are very, very small. Four of us live there but our consumption combined doesn't come close to the energy my mum uses, and I only come back to stay with her and my step dad two or three days a week.

I found out today that our bill is estimated. My mum's told me to knock this on the head by sending in meter readings but I'm still not entirely sure what to ask the company over the phone or how I sort this out once and for all. Of course, nothing much can be done until I see exactly what's on the bill.

I would call the company and explain that your bill is estimated and that you'd like to send in meter readings - they'll be able to explain the procedure for this. In the meantime, keep up what you're doing with switching lights off at all times. Make sure computers, Sky/Virgin boxes and televisions are shut down/turned off fully rather than just being on stand by overnight.

I'm with EDF and NPL, and always have to make sure I write down then figures on the meters because I had this happen to me, they take estimated readings which are really high and then you have to call them up with the correct figures so that they can send an amended bill out.